Imino Glycals via Ruthenium-Catalyzed RCM and Isomerization
作者:Bernd Schmidt、Sylvia Hauke、Nino Mühlenberg
DOI:10.1055/s-0033-1338615
日期:——
enamides via a ruthenium-catalyzed assisted tandem catalytic ring-closing metathesis–isomerization sequence. The sequence relies on the in situ transformation of a metathesis active Ru–carbene into an isomerization active Ru–hydride by addition of hydroxide as a chemical trigger. N-Allyl-N-homoallylamines were converted in one step into cyclic enamides via a ruthenium-catalyzed assisted tandem catalytic
Complementary routes to both enantiomers of pipecolic acid and 4,5-dihydroxypipecolic acid derivatives
作者:Shital K. Chattopadhyay、Titas Biswas、Tanmoy Biswas
DOI:10.1016/j.tetlet.2007.12.097
日期:2008.2
Complementary new routes to bothenantiomers of N-protected pipecolicacid and the corresponding 4,5-dihydroxylated derivatives are developed, which involve stereo-divergent allylation of a chiral N-allylimine and ring-closing metathesis as key steps.
Microwave-assisted synthesis of α-ethoxycarbamates
作者:Alexandre Lumbroso、Floris Chevallier、Isabelle Beaudet、Jean-Paul Quintard、Thierry Besson、Erwan Le Grognec
DOI:10.1016/j.tet.2009.09.023
日期:2009.11
An efficient and reproducible synthesis of various alpha-ethoxycarbamates is described via a microwave heating mode. Compared to the thermal process. the microwave dielectric heating induces a dramatic reduction of the reaction time and the improvement of the yields. The reaction is general since applicable to aromatic and aliphatic aldehydes with various primary amines. Several examples involving chiral aldehydes have also been considered. (C) 2009 Elsevier Ltd. All rights reserved.